The present invention concerns improvements in or relating to the controlled ripening of produce and fruits, etc. More particularly, the present invention is concerned with plastics material containers or bags, both rigid and flexible, for encasing fresh produce and fruits.
There are various known procedures available for the packaging of produce. However, such procedures do not effectively control the ripening of produce and fruits without damage to the produce and fruits.
The present invention seeks to provide a container or bag which enables the internal atmosphere to be modified as desired and thereby eliminate the problems associted with produce packed in a totally sealed package where over-modification of internal atmospheres occurs.
In relation to the provision of a container or bag in accordance with the present invention one must firstly consider the various problems associated in the packaging of produce. Firstly, live produce such as fruit and vegetables, unlike dead material such as meats, have respiration in that they absorb oxygen and give off carbon dioxide. When covered with a film, the atmosphere within the packing or wrapping changes. Most thin films are permeable, but even thin gauge stretch polyvinylchloride is not sufficiently so to cope with most live products. The change that takes place within the packs is called modified atmosphere (MA).
When the levels of carbon dioxide within the pack has reached over five percent and the oxygen in the pack has been lowered to eight percent, the internal atmosphere within the pack has modified to an extent where the process of ripening of the produce or fruits has been significantly slowed.
If the levels of oxygen within the pack are allowed to reduce below four percent and the levels of carbon dioxide increase above six percent, then permanent damage to the produce or fruits will occur.
There will be off odours (alcoholic) present in the pack, the product will have a bitter, and musty taste and its ripening permanently suspended.